Mass Casualty and Triage
Introduction
Mass casualties have the potential to rapidly overwhelm multiple
levels of care and evacuation. Because the Joint Theater Trauma
System (JTTS) has been adapted to provide rapid movement of
casualties through the continuum of care, mass casualty events
may occur at military treatment facilities with little or no advance
notice. Asymmetric warfare may further complicate the mass
casualty event by inclusion of combatant, noncombatant, or third
country nationals among the injured. The mass casualty demands
a rapid transition from routine to contingency medical operations
triggered by the earliest recognition of this specter within the fog
of war. The transition will be eased by a mass casualty response
plan that must be designed, exercised, and assessed to reflect
relevant site and evacuation capability.
A mass casualty event overwhelms immediately available
medical capabilities to include personnel, supplies, and/
or equipment.
Effective mass casualty response is founded on the principle of
triage, the system of sorting and prioritizing casualties based on
the tactical situation, mission, and available resources. It is the
best means to establish order in a chaotic environment and the
best hope to provide the greatest good to the greatest number
within the limitations of time, distance, and capability. Triage is
a constant and dynamic process as casualties move within and
through the system of care.

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Emergency War Surgery

The ultimate goals of combat medicine are the return of the
greatest possible number of warfighters to combat and the
preservation of life, limb, and eyesight.
The decision to withhold care from a casualty who in another
less overwhelming situation might be salvaged is difficult for any
physician, nurse, or medic. Decisions of this nature are unusual,
even in mass casualty situations. Nonetheless, the overarching
goal of providing the greatest good to the greatest number
must guide these difficult decisions. Commitment of resources
should be decided first based on the mission and immediate
tactical situation and then by medical necessity, irrespective of
a casualty’s national or combatant status.
Triage Categories
It is anticipated that triage will be performed at all levels.
Traditional categories of triage are immediate, delayed, minimal, and expectant.
 Immediate: This group of injured requires attention within
minutes to 2 hours on arrival to avoid death or major disability.
The procedures in this category should focus on patients with a
good chance of survival with immediate intervention. Injuries
include:
o Airway obstruction or potential compromise.
o Tension pneumothorax.
o Uncontrolled hemorrhage.
o Torso, neck, or pelvis injuries with shock.
o Head injury requiring emergent decompression.
o Threatened loss of limb.
o Retrobulbar hematoma.
o Multiple extremity amputations.
 Delayed: This group includes those wounded who are in
need of surgery, but whose general condition permits delay in
treatment without unduly endangering life, limb, or eyesight.
Sustaining treatment will be required (eg, fluid resuscitation,
stabilization of fractures, and administration of antibiotics,
bladder catheterization, gastric decompression, and relief of
pain). Injuries include:
o Blunt or penetrating torso injuries without signs of shock.
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Mass Casualty and Triage

o Fractures.
o Soft-tissue injuries without significant bleeding.
o Facial fractures without airway compromise.
o Globe injuries.
o Survivable burns without immediate threat to life (airway,
respiratory) or limb.
 Minimal: This group has relatively minor injuries (eg, minor
lacerations, abrasions, fractures of small bones, and minor
burns) and can effectively care for themselves or be with
minimal medical care. These casualties may also provide a
resource for manpower to assist with movement or potentially
even care of the injured. When a mass casualty incident
occurs in close proximity to a medical treatment facility
(MTF), it is likely that these will be the first casualties to
arrive, bypassing or circumventing the casualty evacuation
chain. Such casualties may inundate the facility leading to
early commitment and ineffective utilization of resources.
To prevent such an occurrence, it is imperative to secure
and strictly control access to the MTF immediately upon
notification of a mass casualty event.
 Expectant: This group has injuries that overwhelm current
medical resources at the expense of treating salvageable
patients. The expectant casualty should not be abandoned,
but should be separated from the view of other casualties
and intermittently reassessed. These casualties require a
staff capable of monitoring and providing comfort measures.
Injuries include:
o Any casualty arriving without vital signs or signs of life,
regardless of mechanism of injury.
o Transcranial gunshot wound (GSW) with coma.
o Open pelvic injuries with uncontrolled bleeding and class
IV shock.
o Burns without reasonable chance for survival or recovery.
o High spinal cord injuries.
Triage Management
Those previously classified as minimal injuries that are evacuated
to a surgical unit should not be brought through the resuscitation
area. These casualties should be diverted to an area near the
facility where they are reassessed, receive care—and, condition
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Emergency War Surgery

permitting—be available to assist with movement of the severely
injured. The remaining casualties should be divided into three
categories: emergent, nonemergent, and expectant. These
categories are useful in dividing casualties into those requiring
further immediate surgical treatment (emergent), and those that
are less injured, still require care in the near term (6–12 hours),
but have low expected mortality (nonemergent). It is anticipated
that 10%–20% of casualties presenting to a surgical unit will
require urgent surgery, but this is incident dependent. The vast
majority of the wounded will not require intensive decisionmaking, intervention, and care.
Triage is a fluid process at all levels, with altered situations and
resources requiring a change in category at any time and in any
setting. In the extreme example, a casualty may be triaged from
emergent to expectant during surgery, abruptly terminating the
operation (“on-the-table triage”).
Special Triage Considerations
Patients who do not easily fit into the standard categories or who
pose a risk to other casualties, medical personnel, or the treatment
facility may require special consideration.
 Wounded contaminated in a biological and/or a chemical
battlefield environment: These casualties must be
decontaminated prior to entering the treatment facility.
Prehospital care may be provided outside of the medical
facility by appropriately protected medical personnel prior
to decontamination.
 Retained, unexploded ordnance: These patients should
be segregated immediately and treated last. See Chapter 1,
Weapons Effects and War Wounds, which describes the special
handling of these wounded.
 Noncombatant local or third country nationals: Due to the
asymmetric nature of modern warfare, these individuals may
be brought into the military trauma system for care during
a mass casualty event that may or may not include United
States or allied forces. Although the mission and tactical
situation must be considered first, in most situations medical
necessity will guide triage decisions. It is crucial to recognize
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Mass Casualty and Triage

the capabilities of local national healthcare resources and
to factor these limitations prospectively into care and triage
decisions. Such decisions must be based on the best and most
timely information available.
 Enemy prisoners of war/internees/detainees: Although
treatment is based on medical necessity, it is essential that
the threat of “suicide bombers” and “human booby traps” be
prevented by carefully screening and disarming all casualties
prior to moving into treatment areas, including the triage area.
See Chapter 32, Care of Enemy Prisoners of War/Internees.
 US, allied, and third nation contractors: Although these
individuals will also receive care based on mission, tactical
situation, and medical necessity, it should be recognized
that less stringent predeployment health assessments or
requirements may permit a population with significant chronic
health co-morbidity to enter a theater of war as a population at
risk. The effect of co-morbidity on survivability may need to be
considered in triage decision-making. (Example: A casualty on
antiplatelet therapy with life-threatening hemorrhagic injury
in a setting where availability of blood components is limited.)
 Combat stress: Rapid identification and immediate segregation
of stress casualties from injured patients will improve the odds
of a rapid recovery. With expeditious care, these casualties can
be returned to duty (80%). Do not use them as litter bearers
because this may increase the trauma you seek to treat.
o Place patient in one of two groups.
♦ Light stress: Immediate return to duty or return to unit or
unit’s noncombat support element with duty limitations
and rest.
♦ Heavy stress: Send to combat stress control restoration
center for up to 3 days reconstitution.
♦ Use the BICEPS mnemonic where resources/tactical
situations allow:
◊ Brief: Keep interventions to 3 days or less of rest, food,
and reconditioning.
◊ Immediate: Treat as soon as symptoms are
recognized—do not delay.
◊ Central: Keep in one area for mutual support and
identity as soldiers.
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Emergency War Surgery
◊ Expectant: Reaffirm that we expect return to duty

after brief rest; normalize the reaction and their duty
to return to their unit.
◊ Proximal: Keep them as close as possible to their unit.
This includes physical proximity and using the ties of
loyalty to fellow unit members. Do this through any
means available. Do not evacuate away from the area
of operations or the unit, if possible.
◊ Simple: Do not engage in psychotherapy. Address
the present stress response and situation only, using
rest, limited catharsis, and brief support (physical and
psychological).
◊ Or refer: Must be referred to a facility that is better
equipped or staffed for care.
If battlefield casualties do not have physical injuries, DO
NOT send them out of the battle area, because this will
worsen stress reactions.
Resource Constraints
Triage decisions are influenced by multiple factors. Areas to
consider include:
 External factors: The surgeon/medic may have limited
knowledge of and no control over external issues. Nonetheless,
optimal casualty care requires at least an assessment of these
factors.
o Tactical situation and the mission: The decision to commit
scarce resources cannot be based on the current tactical/
medical/logistical situation alone. One severely wounded,
resource-consuming casualty may deplete available
supplies and thus prevent future, less seriously injured
casualties from receiving optimal care. Liaison with the
tactical force operating in your area is essential to making
sound triage decisions. Operational security may make this
kind of information difficult to obtain in a timely fashion.
Education of, and communication with, line commanders
about the critical nature of this information is essential.

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Mass Casualty and Triage

o Resupply: Having a sense of how and when expended
internal resources will be resupplied may prove critical
to making the decision to treat or not treat the individual
casualty.
o Time:
♦ Evacuation to the MTF: The shorter the time and
distance interval from injury to arrival will increase the
volume and complexity of triage decisions and increase
the risk of the facility to be overwhelmed by the walking
wounded. Securing the facility and strictly controlling
points of entry are key steps in the execution of a mass
casualty response. Longer intervals will result in the
opposite, with “autotriage” of the sicker patients from
the emergent category to the expectant.
♦ Time spent with the individual casualty: In a mass
casualty situation, time itself is a resource that must be
carefully managed. All patients receive an evaluation, but
only some receive immediate or operative interventions.
Time on the OR table is usually the choke point. Apply the
concepts of damage control to minimize the time casualties
are required to spend in surgery. On-table triage to the
expectant category may be necessary due to deteriorating
casualty physiological response and/or the pattern
of injury (aorta-vena cava GSW, dual exsanguination
sites, extensive pancreatic-duodenal injury, etc).
♦ Evacuation out: Casualties must move expeditiously to
the next level of care, otherwise valuable local resources
will be consumed in maintaining patients, thereby
preventing additional patients from receiving care.
 Internal factors: These issues are known to all medical
personnel and should be factored into triage decisions.
o Medical supplies: These supplies include equipment,
drugs, oxygen, dressings, sutures, sterilization capability,
blood, etc. Immediate liaison with the logistics system
in the MTF and the theater of operation is essential to
ensure the availability and timely resupply of these
items, to include “surge” capabilities and local resource
availability. Blood products may be scarce in an immature
theater or during accelerated consumption in the case of
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Emergency War Surgery

mass casualty. Hemostatic or damage control resuscitation
may be precluded by the availability of hemostatic
transfusion components (plasma, platelets, cryoprecipitate).
Transfusion medicine in the theater of war has in the past
and will likely continue in the future to rely on the walking
blood bank. It is crucial that expeditionary medical units
have a system in place for effective and expedient execution
of a fresh whole blood drive. Early consideration of a fresh
whole blood drive should be included in the response to a
mass casualty.
o Space/capability: This category includes the number of OR
tables and ICU beds (holding capacity and ward capacity), the
available diagnostic equipment—ultrasound, X-ray, CT—and
laboratory tests. For example, if your MTF has the only CT
scanner in theater, plan for an increased number of head-injured
patients. Early in the mass casualty response, an assessment
should be made to clear occupied beds in the hospital,
either by discharge or potential transfer of patients to other
appropriate treatment facilities within theater. This should
be accomplished in coordination with the theater medical
regulator and occur as soon as possible following notification.
o Personnel: This includes knowing the professional
capability (type and experience of individual physician/
nurse/medic), and the emotional stability, sleep status,
etc, of your personnel. This perishable resource must be
preserved; for example, 24 hours of continuous operation
may exhaust your only OR crew and may necessitate
diversion of casualties to another facility. A response plan
should include means to sustain and refresh the staff with
hydration and energy-dense foods during extended periods
of high activity. Robust and practical plans for personnel
recall must be a component of the mass casualty response
plan. Also recognize that medical professionals may possess
a range of skill sets that is not reflected in their deployment
specialty (eg, the Reserve Component physician who is a
general surgeon in civilian practice, but who is assigned
as a general medical officer or flight surgeon). Identifying
and including these individuals as appropriate in a mass
casualty response is a force multiplier.
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Mass Casualty and Triage

o Stress: Soldiers, including medical personnel, are affected
by the consequences of war; individual and unit capabilities
are degraded during sustained operations. The personal
impact of military triage on the medical team cannot be
overemphasized. It is extremely emotional, and measures
should be undertaken to minimize these effects. This is best
provided by trained staff. Cohesive groups may tolerate
stress better and assist each other in dealing with traumatic
events when allowed to process the event in a group format
according to their own traditions.
Triage Decision-Making
The complexity of decision-making in triage varies greatly, often
depending on the level of training and experience of the triage
officer, as well as the location where the triage decision is being
made. In the emergent treatment area, the surgeon (ie, surgeon
of the day; SOD) must make decisions about whether surgery is
needed, the timing of the surgery, and the priority of multiple
surgical patients. Regardless of the type of triage decision needed,
the following information is of critical importance in reaching
that decision:
 Initial vital signs: Pulse (rate and quality), mentation, and
difficulty breathing (eg, a casualty with normal mentation and
radial pulse quality is nonemergent). Respiratory rate alone
is not predictive of the appropriate triage category.
 Pattern of injury: A historical perspective aids the triage
decision-maker in understanding the distribution of wounds
encountered on the modern battlefield and the likely mortality
associated with those wounds. The majority of combat
wounded will suffer nonfatal extremity injuries. In general,
these will be triaged as nonemergent.
 Response to initial intervention: Does the shock state improve,
remain unchanged, or worsen with initial resuscitative efforts?
A patient who fails to respond rapidly to initial resuscitation
should be triaged ahead of a patient with a good response;
alternatively, this nonresponder in a mass casualty situation
may need to be placed in the expectant category.
Data from more recent American combat operations in Iraq
(Operation Iraqi Freedom) and Afghanistan (Operation Enduring
37

*A casualty may have more than one type of injury. These numbers are based
on 1,530 Role 3 injuries.
Data source: Emergency War Surgery, Third United States Revision. Washington, DC:
Department of the Army, Office of The Surgeon General, Borden Institute; 2004.

Setup, Staffing, and Operation of Triage System
 Initial triage area.
All casualties should flow through a single triage area and
undergo rapid evaluation by the initial triage officer. Casualties will then be directed to separate treatment areas (emergent,
nonemergent, and expectant), each with its own triage/team
leader. The expectant will have a medical attendant, ensuring
monitoring and optimal pain control. The dead should be sent
to the morgue and must remain separate from all other casualties, especially the expectant. Unidirectional flow of patients
is important to prevent clogging the system. Reverse patient
flow in any treatment area is highly discouraged.
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